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USDA Wildlife Services: Staff Publications

Series

2001

Aquaculture

Articles 1 - 2 of 2

Full-Text Articles in Physical Sciences and Mathematics

Great Egret Preference For Catfish Size Classes, Scott J. Werner, Mark E. Tobin, Paul B. Fioranelli Mar 2001

Great Egret Preference For Catfish Size Classes, Scott J. Werner, Mark E. Tobin, Paul B. Fioranelli

USDA Wildlife Services: Staff Publications

Several species of fish-eating birds are commonly observed near aquaculture facilities in the southern United States. An understanding of the relationships between these birds and specific commodities is needed to interpret and manage bird impacts to aquacultural production. We conducted two foraging experiments to evaluate the preference o f Great Egrets (Ardea alba) for three specific size classes of Channel Catfish (Zctalurus punctatus). During six no-choice feeding trials, egrets consumed significantly more small (7.5-10 cm) fingerlings than medium (13- 18 cm) or large (23-23 cm) catfish. Egrets captured 19 large catfish, and ingested only two, even …


Daily Activity Budgets And Population Size Of American White Pelicans Wintering In South Louisiana And The Delta Region Of Mississippi, D. Tommy King, Scott J. Werner Mar 2001

Daily Activity Budgets And Population Size Of American White Pelicans Wintering In South Louisiana And The Delta Region Of Mississippi, D. Tommy King, Scott J. Werner

USDA Wildlife Services: Staff Publications

Twenty-one American White Pelicans (Pelecanus erythrorhynchos) were captured and fitted with radio-transmitters in South Louisiana and the delta region o f Mississippi during the winter and early spring of 1994-1997. The pelicans were monitored to determine their daily activity budgets while using different habitats such as catfish ponds, crawfish ponds, rivers, lakes, and bayous. Pelicans foraging at catfish ponds spent about 4% of their day foraging and 96% loafing, while pelicans foraging in other habitats spent about 28% of their day foraging and 72% loafing. For an individual bird, the mean number of foraging sessions per day was …